1. Technical Field
The present invention relates to a wiring board for connection of an electro-optical panel, an electro-optical device employing the connection wiring board, and an electronic apparatus employing the electro-optical device.
2. Discussion
A liquid crystal panel is one example of conventional electro-optical panels. Liquid crystal panels are grouped into active-matrix type liquid crystal panels and passive-matrix type liquid crystal panels. An active-matrix type liquid crystal panel has switching devices provided in one-to-one relation to pixel electrodes. The switching devices are constituted by, for example, TFD (Thin Film Diode) devices. A passive-matrix type liquid crystal panel has no switching devices.
Such a liquid crystal panel comprises a pair of transparent substrates bonded to each other. The liquid crystal panel includes scanning lines formed on a surface of one of the transparent substrates facing the other, and data lines formed on a surface of the other transparent substrate facing the one. Namely, the scanning lines and the data lines are formed on the separate boards.
In a conventional liquid crystal panel, therefore, a first connection wiring board (e.g., an FPC (Flexible Printed Circuit) board) is connected to an upper transparent substrate from below. On the other hand, a second connection wiring board is connected to a lower transparent substrate from above. A group of terminals on each connection wiring board are inserted into a corresponding connector mounted on an external control circuit board.
For carrying out inspection, adjustment, various tests, etc. of a liquid crystal panel, it is often required to remove terminals of each connection wiring board from a connector of a control circuit board and conversely to insert the terminals of the connection wiring board into the connector of the control circuit board in a condition where both connection wiring boards are connected to the liquid crystal panel.
With the connection wiring boards having the above-described construction, however, the following problems occur.
(1) The control circuit board including connectors requires two connectors for two connection wiring boards. In other words, two connectors are required to connect the first connection wiring board to the control circuit board and connect the second connection wiring board to the control circuit board, respectively. This increases the number of parts.
(2) Groups of terminals on both connection wiring boards must be inserted and removed into and from the two connectors. Inspection, adjustment, various tests, etc. of a liquid crystal panel therefore become troublesome to carry out.
One object of the present invention is to provide a connection wiring board for connection of an electro-optical panel, which can be connected by one operation to, e.g., a member for driving the electro-optical panel.
Another object of the present invention is to provide an electro-optical device which employs the wiring board for connection of an electro-optical panel according to the present invention, and can be manufactured with ease.
Still another object of the present invention is to provide an electronic apparatus employing the electro-optical device according to the present invention.
The present invention resides in a wiring board for connection of an electro-optical panel, the connection wiring board being connected to an electro-optical panel having a pair of opposed substrates, the connection wiring board comprising:
a first base material, wiring having a predetermined pattern, and a second base material;
a first terminal group provided on the first base material;
a second terminal group provided on the second base material; and
a third terminal group provided on the first base material or the second base material;
the third terminal group including at least terminals electrically continuous to the first terminal group and terminals electrically continuous to the second terminal group.
In the wiring board for connection of an electro-optical panel according to the present invention, the third terminal group includes at least terminals electrically continuous to the first terminal group and terminals electrically continuous to the second terminal group. With the present invention, therefore, the first terminal group and the second terminal group can be electrically connected to, for example, a member (e.g., a control circuit board) for driving the electro-optical panel by one operation.
The wiring board for connection of an electro-optical panel according to the present invention is preferably implemented in any of the following forms (a) to (j).
(a) The wiring board for connection of the electro-optical panel has a multilayered structure including the first base material, the wiring, and the second base material in at least a part of the connection wiring board. In the part where the multilayered structure is constructed, one of the two base materials can function as a protective layer for the wiring formed on the other base material.
(b) Preferably, a connection surface of the first terminal group and a connection surface of the second terminal group are oriented in opposed directions. With this feature, the first terminal group and the second terminal group can be easily connected to the opposed surfaces of both the boards of the electro-optical panel, respectively.
(c) Preferably, the first terminal group is exposed to the outside due to the absence of the second base material. The exposed first terminal group enables the electro-optical panel and the first terminal group to be connected more easily.
(d) Preferably, the second terminal group is exposed to the outside due to the absence of the first base material. The exposed second terminal group enables the electro-optical panel and the second terminal group to be connected more easily.
(e) Preferably, the first base material is formed of a flexible insulating film. With this feature, when the wiring board for connection of the electro-optical panel is connected to the electro-optical panel, the connection wiring board can be flexibly deformed. As a result, the wiring board for connection of the electro-optical panel can be more easily connected to the electro-optical panel.
(f) Preferably, the second base material is formed of a flexible insulating film. With this feature, when the wiring board for connection of the electro-optical panel is connected to the electro-optical panel, the connection wiring board can be flexibly deformed. As a result, the wiring board for connection of the electro-optical panel can be more easily connected to the electro-optical panel.
(g) The wiring can be formed of a material mainly containing any of copper, copper alloys (such as bronze, brass and beryllium copper), aluminum, aluminum alloys, gold, and silver.
(h) Further, the wiring board for connection of the electro-optical panel according to the present invention can be implemented in any of the following forms.
{circle around (4)} The wiring in the first terminal group and the wiring in the second terminal group are positioned in the same layer. With this form, the first terminal group and the second terminal group can be formed in the same patterning step.
{circle around (2)} The first base material further includes a fourth terminal group electrically continuous to the first terminal group; and
the second base material further includes a fifth terminal group electrically continuous to the third terminal group,
the fifth terminal group being electrically continued to the fourth terminal group.
In this form, the wiring board for connection of the electro-optical panel can be manufactured by connecting the first base material having the wiring formed thereon and the second base material having the wiring formed thereon such that the fourth terminal group and the fifth terminal group are electrically continuous to each other. As a result, the wiring board for connection of the electro-optical panel can be manufactured with ease.
(i) Moreover, the connection wiring board further comprises a sixth terminal group electrically continuous to the third terminal group. In this form, signals (e.g., scanning signals or data signals) can be input to the electro-optical panel with, for example, the first terminal group or the second terminal group and the sixth terminal group.
(j) Preferably, a shape of the first base material and a shape of the second base material are substantially the same except for the terminal groups. With this feature, one of the two base materials can function as a protective layer for the wiring formed on the other base material except for the terminal groups thereon.
The present invention also resides in an electro-optical device including an electro-optical panel having a first substrate and a second substrate opposed to each other, wherein:
the first substrate has a first connection terminal area not overlapping the second substrate;
the second substrate has a second connection terminal area not overlapping the first substrate;
the first connection terminal area and the second connection terminal area are electrically connected to the connection boards for wiring of the electro-optical panel according to the above described present invention;
a first terminal group on the connection wiring board is electrically connected to the first connection terminal area; and
a second terminal group on the connection wiring board is electrically connected to the second connection terminal area.
The electro-optical device of the present invention includes the wiring board for connection of the electro-optical panel according to the present invention. Hence, the wiring board for connection of the electro-optical panel and a member (e.g., a control circuit board) for driving the electro-optical panel can be connected to each other with the third terminal group by one operation. As a result, the wiring board for connection of the electro-optical panel and the member for driving the electro-optical panel can be easily attached and detached. Also, the electro-optical device can be simply manufactured with a high yield.
The electro-optical device according to the present invention is preferably implemented in any of the following forms (a) to (d).
(a) At least one of connection between the first terminal group and the first connection terminal area and connection between the second terminal group and the second connection terminal area is established using an anisotropic conductive adhesive. With this feature, such a connecting step can be simplified.
(b) The electro-optical device is preferably employed as a liquid crystal device. When the electro-optical device is employed as a liquid crystal device, it is possible to more effectively develop the function of the electro-optical device.
(c) Data lines are provided in the first terminal group and scanning lines are provided in the second terminal group. In this form, data signals can be input to the first terminal group and scanning signals can be input to the second terminal group.
(d) A semiconductor device can be mounted in at least one of the first connection terminal area and the second connection terminal area. The semiconductor device may comprise, e.g., a driver IC.
An electronic apparatus of the present invention includes any of the above electro-optical devices according to the present invention. This feature improves, for example, convenience of the electronic apparatus based on the advantage of the electro-optical device according to the present invention. Also, the electronic apparatus can be simply manufactured with a high yield.
Hereinafter, the wiring board for connection of the electro-optical panel according to the present invention will be referred to as the xe2x80x9cconnection wiring boardxe2x80x9d.